The present invention relates to materials and methods for inducing in situ transitions of a hydrogel precursor compositions from an injectable state to a hydrogel.
A mechanism for gently transitioning a hydrogel precursor composition from a liquid state to a solid state such that the transition can be carried out in situ, directly in intimate contact with sensitive biological materials, is of special interest for medical purposes. After being delivered in a liquid state, the in situ formation of a hydrogel at an implantation site has two potential advantages: the ability to match the morphology of a material implant to various complex tissue shapes in the body, and the ability to deliver a large device through a small hole in the body via minimally invasive surgery (Hubbell, MRS Bulletin, November issue, 33-35, 1996). In addition, this type of transitioning system can be used as a carrier for the controlled release of drugs, for the delivery of living cells in cell transplantation, as a barrier for the prevention of postoperative adhesions, or as a structural support at tissue sites.